Increasingly aggressive medical treatment has resulted in a dramatic rise in the number of childhood cancer survivors over the past two decades. While "cured" of cancer, these children and adolescents are at risk for significant medical and psychological sequelae. In the present study, we propose and test a post-traumatic stress model for understanding, predicting and treating emotional consequences of childhood cancer treatment. Intensive cancer treatment is intrusive and includes multiple and prolonged hospitalizations, repeated painful procedures, and generalized family distress over a period of several years. Four hundred pediatric oncology patients, age 8-18, disease free and off treatment for at least two years, and their parents, recruited from The Children's Hospital of Philadelphia and the University of California at Los Angeles will complete paper and pencil measures of anxiety, posttraumatic stress, social support, and family functioning. An interview measure of anxiety in children will be administered to a randomly selected subset of 125 subjects and their parents. Equivalent numbers of matched controls, recruited from the pediatric clinics at both centers, will be used as a comparison group for both paper and pencil and interview portions of the study. The presence of anxiety and specific post-traumatic stress symptoms in the sample of cancer survivors will be compared with that in the control group. The relationship of post-traumatic stress symptoms to intensity of treatment, medical sequelae of treatment, and family and social support variables in survivors will also be explored. Through the identification of the prevalence and correlates of anxiety in pediatric oncology survivors and their parents, interventions to remediate the associated distress can be designed.